Time-resolved laser-induced fluorescence of asbestos in visible region

Ozu, Akira  ; Esaka, Fumitaka  ; Yasuda, Kenichiro   

Nanosecond time-resolved laser-induced fluorescence spectroscopy was performed on five kinds of asbestos materials (chrysotile, crocidolite, amosite, tremolite and anthophyllite) using a ultra-violet laser pulse of 266 nm. Most of the fluorescence spectra had a broad wavelength band of 350-700 nm and a maximum near around 450 nm in the visible region. The spectra also varied in shape over time. Although all the spectra were similar in shape, a significant difference in the relative ratio of fluorescence intensity between the two different wavelength regions was identified. The lifetime and total amount of fluorescence intensity were also investigated and the differences were observed for the different kinds of asbestos. Several methods potentially useful for discriminating asbestos from other materials through use of their fluorescence characteristics are discussed.